Composite paving block



Feb. 24, 1931.

E. c. WALLACE w 1,794,220 concurs PAVING BLOCK s sheet-sheet 1 mm! Nov.5, 1927 INVEN TOR. Sam/w C. ewazem,

rm MM Um M ATTORNEY Feh 24, 1931. E. c. WALLACE Filed Nov. 5, 1927 3Sheets-Sheet 2 I INVENTOR. /dw/ixw 900580.68,

BY a} mam M ATTORNEY E. C. WALLACE COMPOSITE PAVING BLOCK 3 Sheets-Sheet3 Filed Nov INVENTOR.

ATTORNEY Feb 24, 1931 Patented Feb. 24, 1931 PATENT OFFICE EDWIN C.WALLACE, OF NEWTON, MASSACHUSETTS COMPOSITE PAVING BLOCK Applicationfiled November 5, 1927. Serial No. 231,285.

This invention relates to improvements in composite paving blocks andmore particularly to blocks of this character cons sting of asubstantially rigid body and a resilient surface member, designed andconstructed to sustain heavy loads and to resist the thrust of the fastmoving vehicles of modern trafiic.

Heavy loads moving at high speeds have developed new problems in thepaving industry. Road construction which formerly was consideredsuitable for heavy traflic has been found to be entirely inadequate forpresent day tralfic conditions.

The desirable qualities of rubber and rubher compositions as surfacingmaterial for streets and roads has long been recognized, but the veryproperties to which the wear resisting qualities of such material aredue have retarded its adoption as a pavlng material owing to thedifliculty of attaching it to a suitable base or support in such mannerthat it cannot be displaced by the thrust of fast moving vehicles.

It has been found that this tendency of the rubber surfacing element ormat to become displaced could be overcome by securely attaching it to abody such as a paving block, which of itself possesses considerableweight and can readily be secured in place upon a suitable supportingbed or foundation. It was also found, however, that although the generalidea of such construction, in the main, was excellent, the design of therubber or resilient mat and the method of attaching it to the block werevery important factors.

It is therefore the object of the present invention to provide animproved design of block and mat and improved means for securelyattaching the mat to the block whereby the difiiculties and objectionsheretofore encountered are effectually overcome.

With the foregoing and other objects in view, the invention consists inthe novel construction and method hereinafter more particularlydescribed and shown in the accompanying drawings, in which Fig. 1 is atop plan view of one form of the blocks showing in broken lines onedesign or configuration of the attaching member of the mat.

Fig. 2 is a horizontal sectional view of this block taken on the lineA-A of Fig. 3.

Fi 3 is a vertical sectional view taken on the l1ne BB of Fig. 1.

Figs. 4, 5 and 6 are plan views of the form of the block shown in Fig. 1with parts broken away and in section showin variations in the design orconfiguration of the attaching member of the mat.

Fig. 7 is a vertical section of a block showing a modified form of mat.

Fig. 8 is a horizontal sectional view taken on the line CC of Fig. 7

Fig. 9 is a view similar to Fig. 7 showing another modified form of mat.

In the drawings above briefly described, the preferred forms ofconstruction have been illustrated and while these constructions will bespecifically described, it is to be understood that within the scope ofthe invention as (plaimed, numerous variations may be ma e.

Referring to the drawings 1 denotes the body or base member of the blockand 2 denotes the mat or resilient surface member of the block. The bodyor base of-the block may be of any desired size and shape but polygonalshapes having angles greater than 90 to facilitate casting or molding,are preferred. Hexagonal or octagonal shapes are also preferred overother forms since such blocks having all faces equal can be more easilymade and more readily laid and securely held in position by surroundingblocks. The mat or resilient surface member 2 of the block is formed ofa suitable rubber com position and conforms in shape to theconfiguration of the base or body portion 1, to which it is secured, andmay vary in thickness from A; to of an inch or more, but by preferencefor general use is made about inch thick.

In order to firmly secure the mat'to the body of the block, the mat isprovided on its inner side with one or more integral ribs orprojections. In the form of the blocks illustrated in Figs. 1 to 6 ofthe drawing, the mats are shown as having but one centrally disposed rib3 which is preferably made continuous and spaced inwardly from the sideedges of the mat and outlines a space,

the center of which is co-incident with the center of the mat, but maybe of any desired configuration which will provide lateral sup portagainst the thrust of trafiic regardless of the direction of the thrust.For instance, the rib or the figure outlined thereby may be hexagonal asshown in Figs. 1, 2 and 3 of the drawings, rectangular as shown in Fig.4, circular as shown in Fig. 5 or triangular as shown in Fig. 6, sinceIn any one of these forms every point of the perimeter is reinforced andsupported laterally by the diagonal, perpendicular, or curvilinear,exten- 4 sions of the rib. These ribs are endless as shown, preferablyabout inch wide and from ,4; to 1 inch or more in height and areundercut on one or both sides as shown at 4 to form a recess into whichthe material forming the base will snugly fit.

In addition to the centrally disposed rib hereinbefore described, themats may be provided with a peripheral rib or flange 5, as shown inFigs. 7,8, and 9. This rib or flange is preferably from to 1 inch highand undercut on its inner side as shown at 6- to form a recess toreceive the material which forms the base. The peripheral flangeoverlaps the edge of the top of the base but the outer surface of theflan e is flush with the outer surface of the base slow the flange.

In Fig. 9 of the drawing, in addition to the peripheral flange 5, themat is provided with a centrally disposed projection 7 having a centralcup-like depression 8 and under cut outer sides as shown at 9 to formrecesses to receive the material forming the base.

Since pavement blocks are subjected to the thrust of trafiic from alldirections, it is essential, if they embody a resilient surface element,that that element be effectively anchored to its base. It is for thisreason, therefore, that the anchoring rib of the rubber element in thepresent invention is inset from the bounding edges of the body portionof the element and arranged to bound a space approximately in the centerof the body element. This space is thus filled with the unyieldingmaterial of the base element and the rib is reinforced throughout, ontheinside and on the outside as well, by reason of being inset from theedges. Thus a sudden blow or thrust which might result in dislocation orloosening of the rubber surfacing member, under the conventional formsof anchoring, is prevented from so doing in the present invention byreason of the rib being embraced throughout with the material of thebase element. The rib being endless, it is, at the point where a blow orthrust may be'applied, always transverse to the line of such blow orthrust which also increases its resistance to dislodgment.

In producing this composite block, the mat of rubber composition whichforms the surface member 2 is first formed and is then placed in thebottom of a mold of the desired size and shape, with the rib and flanbearing side u permost. The materia from which the ase or body 1 of theblock is formed is then cast or pressed in the mold to snugly fit intothe recesses formed b the undercut sides of the ribs and flan es. fterthe block has become set or bar ened so it can be handledwithout,distortion, it is removed from the mold.

While it is advisable to store the blocks for some time before using, itis not necessary that this be done for any fixed period of time.

I claim A composite paving block comprising a base of hard material ofthe character of stone, and a surface member of resilient material ofthe character of rubber, the surface member having an anchoring ribembedded a substantial depth in and fully embraced by the hard material,said rib being inset from the periphery of the surface member, ofendless form and bounding a. comparatively iarge space at the center ofthe surface mem- In testimony whereof I aflix my signature.

EDWIN C. WALLACE.

